<?php
/**
 * Created by PhpStorm.
 * User: kb130
 * Date: 2017/8/21
 * Time: 15:25
 */

namespace util\validate\rules;

/**
 * 验证值为null
 *
 * Class Nullable
 * @package validate\rules
 */
class Nullable extends BaseRule
{
    public function verify()
    {
        return is_null($this->value);
    }
}